During the paint fabrication process, a tank containing a mix of minium (red lead) and glycerophthalic resin exploded at 11 pm. The ensuing fire destroyed 2 workshops and both the research and control laboratories; 170 employees were in technical unemployment. Initiated at 6 am, production was suspended due to a lack of solvent scheduled for delivery. The stirring operation was stopped at 9:30 am. After heating, the tank was cooled at 4 pm by sprinkling water and subsequently monitored. No other anomaly was detected thereafter until the explosion. The oxidation of drying oils contained in the resin had caused the formation of fatty acids, lead salts, followed by aldehydes, at the low ignition point, with these components collecting at the top of the tank and then inflamed.